气液两相旋转爆轰波不稳定传播模态机制研究

Continuous rotating detonation engine is a new concept engine based on detonation combustion mode, which has the advantages of high thermal efficiency, high specific impulse and compact structure. The generation of instability phenomenon and unstable propagation mode of gas-liquid two-phase rotating detonation wave, will cause the engine to generate eccentric torque to form high-frequency vibration, and the energy loss reduced engine performance significantly. The instability phenomenon of gas-liquid two-phase rotating detonation wave and the mechanism of unstable propagation mode are the main research contents of this project. Firstly, the influence of mixing characteristic of two-phase mixed gas on the propagation stability of detonation wave is studied, and the influence of detonation wave, oblique shock and contact discontinuity on the instability is explored. The instability phenomena such as reverse, quenching and re-initiation of gas-liquid two-phase rotating detonation wave are experimentally studied to reveal the mechanism of instability of rotating detonation wave. Experimental studies on the unstable propagation modes of gas-liquid two-phase rotating detonation wave are carried out. The propagation characteristics of detonation wave in single/dual-wave hybrid mode and double-wave collision mode are analyzed to reveal the formation mechanism of two kinds of unstable propagation modes. Grasping the influence law of the unsteady flow of two-phase mixed gas on the propagation stability of the rotating detonation wave, and avoiding the generation of the unstable propagation mode, will provide a theoretical basis for the further research on the continuous rotating detonation engine.

连续旋转爆轰发动机是一种基于爆轰燃烧模式的新概念发动机，具有高热效率、高比冲、结构紧凑等优点。气液两相旋转爆轰波失稳现象以及不稳定模态的产生，会导致发动机产生偏心力矩形成高频振动，且能量内损较大发动机性能大幅降低。本项目研究内容主要为：气液两相旋转爆轰波失稳现象，以及不稳定传播模态的产生机制。首先研究两相混气掺混特性对爆轰波传播稳定性的影响，探索爆轰波、斜激波和接触间断等相互作用对失稳的影响规律。实验研究气液两相旋转爆轰波反向、熄爆和再起爆等失稳现象，揭示旋转爆轰波失稳现象的产生机理。实验研究气液两相旋转爆轰波不稳定传播模态，分析混合单双波模态和双波对撞模态下爆轰波传播特性，揭示两种不稳定传播模态的形成机制。掌握两相混气非定常流动等因素对旋转爆轰波传播稳定性的影响规律，避免不稳定传播模态的产生，为连续旋转爆轰发动机的深入研究提供理论依据。

连续旋转爆轰发动机（Continuous Rotating Detonation Engine, 简称 CRDE） 是一种基于爆轰燃烧模式的新概念发动机，具有热循环效率高、比冲高、推力可调等优点，采用直接起爆方式引燃可燃混气，环形燃烧室内形成一个或多个旋转爆轰波面，高温高压爆轰产物膨胀从发动机末端排出形成推力，为新型动力领域的重要发展方向之一。. 本项目开展了环形燃烧室内气液同轴雾化掺混特性研究，分析了喷射角度、相邻喷嘴夹角、背压和气液速度比对雾化特性的影响；搭建了液滴粒径测试系统，分析了不同喷注压力下的雾化流场试验研究。建立了气液两相连续旋转爆轰数值模型，分析了燃料液滴与爆轰波面相互作用过程，描述了气液两相旋转爆轰流场结构。搭建了气液两相连续旋转爆轰发动机实验系统，研究了当量比、质量流量、富氧空气温度、燃烧室长度等参数对气液两相旋转爆轰波传播特性的影响，观察到了不稳定爆轰转单波模态、不稳定爆轰转双波模态、旋转爆轰波时空不稳定、熄爆再起爆、单双波混合模态、双波转单双波混合模态、稳定/不稳定双波对撞模态，分析了各参数对气液两相旋转爆轰波传播稳定性的影响，阐明了气液两相旋转爆轰波不稳定传播模态的产生原因和形成机制。